Suffering makes you weaker: Limited evolutionary adaptation in competitively inferior populations

• Published in: Ecology letters Vol. 27; no. 6; pp. e14457 - n/a
• Main Authors: Chen, Nan, Zhang, Quan‐Guo
• Format: Journal Article
• Language: English
• Published: England Blackwell Publishing Ltd 01.06.2024
• Subjects: Adaptation; Adaptation, Physiological; Biological Evolution; coculture; E coli; Ecological adaptation; Escherichia coli; Escherichia coli - physiology; Evolution; evolutionary adaptation; experimental evolution; extinction; Feedback; Interspecific; interspecific competition; local adaptation; Monoculture; Population number; population size; Population studies; Populations; Pseudomonas fluorescens; Pseudomonas fluorescens - genetics; Pseudomonas fluorescens - physiology; species; Temperature; Temperature gradients; temperature; local adaptation; evolutionary adaptation; experimental evolution; extinction
• ISSN: 1461-023X; 1461-0248; 1461-0248
• DOI: 10.1111/ele.14457

Interspecific competition can hinder populations from evolutionarily adapting to abiotic environments, particularly by reducing population size and niche space; and feedback may arise between competitive ability and evolutionary adaptation. Here we studied populations of two model bacterial species, Escherichia coli and Pseudomonas fluorescens, that evolved in monocultures and cocultures for approximately 2400 generations at three temperatures. The two species showed a reversal in competitive dominance in cocultures along the temperature gradient. Populations from cocultures where they had been competitively dominant showed the same magnitude of fitness gain as those in monocultures. However, competitively inferior populations in cocultures showed limited abiotic adaptation compared with those in monocultures. The inferior populations in cocultures were also more likely to evolve weaker interspecific competitive ability, or go extinct. The possible competitive ability‐adaptation feedback may have crucial consequences for population persistence. Interspecific competition may drive evolutionary niche separation among competing populations which in turn facilitates species coexistence. Evolutionary niche encroachment may also happen, leading to competitive exclusion. The latter process is likely short‐lived and easily overlooked by studies of extant coexisting species. A long‐term experimental evolution study with two model bacterial species demonstrates a “Matthew effect”: competitively dominant populations show faster evolutionary adaptation, become even more competitive, and could drive competitors extinct.